1. Field of the Invention
This invention relates to packaging assemblies for optoelectronic devices. More particularly, the present invention relates to optoelectronic packaging assemblies that provide for optical coupling to an optical fiber and for electrical connections to external components.
2. Discussion of the Related Art
Modern optoelectronic applications frequently involve analog or digital signal communication through optical fibers. Such applications typically include optoelectronic devices, such as laser diodes, LEDs, photodiodes, and phototransistors, as primary components. When using such optoelectronic devices it is often necessary to provide for optical coupling with an optical fiber and to provide for electrical connections to external components. For reliability, sealed packaging assemblies are usually used to mount the optoelectronic device, to protect them, and to assist implementation of the optical coupling and electrical connections.
Unfortunately, optoelectronic packaging has proven to be a demanding, difficult, and costly manufacturing task. One significant problem is coupling an optical fiber to an optoelectronic device with the required alignment accuracy and in such a way that the optical alignment is stable over both time and temperature. Manually aligning optical components is time consuming and costly. To assist optical alignment it is common to insert an optical-coupling ferrule between the optoelectronic component and the optical fiber. But, optical alignment remains a serious problem.
Another problem with optoelectronic packaging is the difficulty of removing heat from a packaged high-power optoelectronic device. For example, a laser diode can produce a significant amount of heat that must be removed quickly and efficiently to protect the laser diode.
Because of the foregoing, optoelectronic packaging assemblies generally have been relatively large, at least in comparison to non-opto semiconductor device packages. Furthermore, automated fabrication processes for use with optoelectronic packaging assemblies have been limited.
One optoelectronic package assembly that has been relatively successful is the so-called butterfly package. That package provides for input/output electrical connections along two sides, a high frequency circuit board for mounting an optoelectronic device and its associated components, and a tube for receiving an optical fiber. The tube enables an optical fiber and an optical ferrule to be located near the optoelectronic device, while the input/output lines enable electrical interconnections. Furthermore, additional mechanical components are required, for example, brackets that retain the optical fiber and ferrule in position.
While generally successful, the butterfly package is characterized by a large number of mechanical parts that must be assembled to a high degree of accuracy in a package that provides for poor access to internal components. Additionally, traditional butterfly packages are costly and inflexible to changes in their structure or configuration. Reference FIG. 1 and the associated detailed description that is provided subsequently.
Therefore, an optoelectronic packaging assembly that provides for input/output electrical connections, for easy mounting of an optoelectronic device and its associated components, for relatively simple, accurate and stable optical alignment, and for good thermal cooling would be beneficial.
The principles of the present invention provide for an optoelectronic packaging assembly with input/output electrical connections, easy mounting of an optoelectronic device, relatively simple, accurate and stable optical alignment between the optoelectronic device and an optical fiber, and good thermal cooling.
A first embodiment optoelectronic packaging assembly that is in accord with the principles of the present invention includes a submount having a cavity defined by a floor, sidewalls, a back wall, and a front wall. The sidewalls retain pins, while the front wall includes a protruding optical input receptacle. The submount fits on sidewalls of a base that includes a front wall with a slot. The base is configured such that the submount extends over the base sidewalls, and such that the optical input receptacle extends from the slot. An external cover fits over the submount.
A second embodiment optoelectronic packaging assembly that is in accord with the principles of the present invention includes a submount having sidewalls, a front wall, pins, protrusions, and an optical input receptacle. The protrusions are dimensioned to receive a printed circuit board. The front wall and the sidewalls define a cavity, and the sidewalls retain the pins. The optical input receptacle extends from the front wall. A bottom cover includes walls configured to receive the submount such that the submount and the bottom cover form an enclosed bottom cavity. Furthermore, the optical input receptacle extends from the bottom cavity. Additionally, a top cover is received on the submount. The top cover and the submount are configured such that the submount and the top cover form an enclosed top cavity.
A third embodiment optoelectronic packaging assembly that is in accordance with the principles of the present invention includes a base having a bottom wall and a front wall with a protruding optical input receptacle. A submount is attached to the bottom wall. Furthermore, a heat-sink mates with the base to form an enclosed volume. The heat-sink includes a top surface with a slot. An insert is in the slot. That insert includes pins that extend into the enclosed volume.
A fourth embodiment optoelectronic packaging assembly that is in accord with the principles of the present invention includes a base having a plate and a front wall with an optical input receptacle. A submount is attached to the plate. A printed circuit board having electrical contacts is on the submount. A heat-sink is in thermal communication with the plate. Pins of an insert electrically connect to the electrical contacts.
Additional features and advantages of the invention will be set forth in the description that follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.